Mickelson's manager confirmed Saturday that the investigation was the same outlined in reports in several newspapers, including the Wall Street Journal.

The newspapers report that federal investigators are looking into the trading patterns of Mickelson and Walters involving two stocks. The newspapers say the FBI and Securities and Exchange Commission are analyzing trades Mickelson and Walters made in Clorox about the time Icahn was attempting to take over the company.

The newspapers cited unidentified law enforcement sources confirming the investigation. The Associated Press couldn't immediately confirm details of the probe.